HONG KONG – Heavy rains across Hong Kong prompted the city’s weather forecaster to issue the year’s first black rainstorm warning for almost two hours on Tuesday morning, disrupting life across the city.

The rains and flooding they caused forced road closures and suspension of ferries in some places, with the Hong Kong Observatory alerting the city dwellers against landslides and urging them to stay away from slopes.

The downpours were particularly heavy in the city’s Eastern and Southern districts.

IN PICTURES: Hard rains

As a precautionary measure, the MTR Corporation, the city's sole railway operator, temporarily shut exits A2 of Sham Shui Po station, B3 of Wong Tai Sin station, and A1 of Choi Hung station.

Under the influence of an area of intense thundery showers over a broad trough of low pressure, showers are particularly heavy over Lamma Island, the observatory said, adding that a severe rainstorm with more than 100 mm of hourly rainfall has been recorded.

Rainwaters submerged an underground parking space at Wan Tsui Estate in Chai Wan, leading the Drainage Services Department to rush teams to pump out the water.

The black rainstorm warning, which was issued at 9:10 am, was downgraded to red at 11:05 am and further to amber by 11:45 am. As the weather improved, the amber alert was canceled at 2:45 pm.

Hong Kong operates a three-tier rainstorm warning system, with black representing the most severe level of rainfall.

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“Though rainstorm warning has been cancelled, under the influence of a broad trough of low pressure, areas of intense thundery showers are still developing over the vicinity of the Pearl River Estuary,” the HKO said in a 3:21 pm bulletin, advising people to stay alert to the danger that may be brought about by river flooding.

According to the Transport Department, services run by Coral Sea Ferry Company from Kwun Tong to Sai Wan Ho, Sai Wan Ho to Kwun Tong, Sam Ka Tsuen to Sai Wan Ho, and Sai Wan Ho to Sam Ka Tsuen were suspended. Meanwhile, the ferry services between Aberdeen and Po Toi Island operated by the Tsui Wah Ferry Service were also halted.

The Education Bureau said schools should implement contingency measures to ensure the safety of students.

Classes at all afternoon schools were suspended. Schools that are in session should continue until the end of school hours, the bureau said, adding that they should ensure the conditions are safe before allowing students to return home.

A man surnamed Chan told China Daily he got caught in the downpour when he tried to leave MTR Tai Po Market Station at around 1 pm for his workplace, a roughly 10-minute walk away.  Stranded by the heavy rain, he said he had to wait under a sheltered walkway outside the station for about 30 minutes, and was still stuck there at 1:30 pm.

Tsang Hin-yuk, a traditional Chinese medicine therapist who commutes between his home in Lai Chi Kok and his office in Admiralty, had to brave the heavy rain, saying his strict workplace policy requires him to punch in by 10:30 am regardless of the weather.

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Luckily, the downpour in that area on Hong Kong Island was less severe. “The downpour had peaked between 7 am and 8 am, but by the time I left home, it had eased significantly,” he said.

According to the observatory, heavy showers associated with a broad trough of low pressure are affecting the coast of Guangdong. Locally, more than 50 mm of rainfall was recorded over most parts of the territory in the past couple of hours, and rainfall even exceeded 70 mm over the eastern part of Hong Kong Island.

At 8 am, Tropical Storm Co-May was centered about 290 kilometers west-northwest of Japan's Okinawa. It is forecast to move west-northwest at about 15 km per hour across the East China Sea, said the observatory.